1. Field of the Invention
The invention relates to an artificial joint system for cement-free implantation, the system including an implant and a clamping device and is suitable, for example, for artificial hip joints, artificial knee joints and artificial elbow joints. This invention covers, in particular, those joint systems which include an intermediate member (bone shaft member) extending in the direction of the bone shaft and supporting a joint head associated with a joint socket and a clamping device with which the intermediate member can be pressed to the bone in the resection plane. The clamping device is understood to also include, in particular, a shaft extending in the longitudinal direction of the long bone and being placeable into a bore of the long bone, the shaft having a head section provided with a threaded bore extending perpendicularly to the resection plane into which bore the intermediate member is screwed. The invention further relates to a method for implanting such a joint system.
2. Background of the Art
It is known that numerous structures of different design are used as artificial joint prostheses. For example, German Pat. No. 2,854,334 discloses a femur-hip joint endoprosthesis which, particularly in the head section of the shaft, has a fill bore into which the spongy tissue can be inserted so as to reach the exterior of the shaft through perforations and thus assure secure growth around the endoprosthesis. In this shaft prosthesis, as well as in the other prior art shaft prostheses with and without collar, there is a greater or lesser amount of unphysiological introduction of force into the long bone, either due to unphysiological radial stresses in the shaft prostheses or due to changes in longitudinal stresses in the long bone, for example, as a result of pretension. Moreover, the prior art clamping systems result in unphysiological introductions of force at the side of the long bone opposite the resection plane and thus result in fault-inducing stresses on the bone. In all prior art artificial joint systems, this results in limited durability which, on the average, today lies between five and ten years.